Kinetics of crystallization in 4BaTiO3-SiO2 glass

We have investigated the kinetics of BaTiO3 crystallization in 4BaTiO3-SiO2 glass. Isothermal and non-isothermal in situ X-ray diffraction (XRD) and differential thermal analysis (DTA) measurements were performed. It has been found that the small particle of BaTiO3 crystals grow up to a size of 30 nm when the sample is annealed from room temperature to 900 °C with a heating rate of 2 K/min. The transformed volume fraction, calculated from the non-isothermal in situ XRD measurements, agrees well with the result of DTA investigation. The Avrami exponent that is used to describe the crystallization kinetics has been determined to be “unity” from isothermal in situ XRD measurements, indicating that the crystallization mechanism is in the diffusion controlled growth with zero nucleation rate.